Piece dyed silk and process



1931- L. N. HOOD ETAL I 1,819,027

PIECE DYED SILK AND PROCESS Filed Oct. 24, 1925 INVENTORS I 2 J mATTORNEYS Patented Aug. 18, 1931 PATENT OFFICE PIECE DYED SILK ANDPROCESS Application filed October 24, 1925. Serial No. 64,526.

This invention relates to a process of dyeing silk in the piece and tothe product obtained thereby. It relates more particularly to theprocess by which silk oods in the piece, or goods containing sili andother fibres, ma be dyed in such a manner that they will e fast towashing in soapy water, even at high temperatures, and will also be fastto perspiration, ironing, salt water and other agencies which usuallycause silk to fade. The process also produces silk goods or goodscontaining silk that are reasonably fast to light. The process isespecially applicable to vat dyes and enables silk goods in pieceto bedyed with these dyes of various colors in such a manner than evenness oruniformity of color is obtained, and the goods are free from splotchesor irregularities.

The invention will be understood from the description of a specificprocess by which the same is carried out, but is not restricted to theparticular procedure outlined below. In practicing the invention, wehave found that the same can be successfully carried out in thefollowing manner: The vat dyestuffs are first reduced and dissolved inthe usual manner, preferably in a small volume of water, with smallamounts of caustic soda and hydrosul hite present. The dyeing may becarried out in a jig made of appropriate material, such as Monel metal,for example, and the process has been successfully used in dyeing piecesof silk varying in length from about to 400 yards. The amount ofmaterials in the. dye bath varies with the amount of the dyestuif thatis required to produce the desired shade.

In making up the dye bath, substantlally the following proportions ofmaterials may .be used:

1 to 4 quarts of 30 B. solution of caustic soda, or other suitablealkali,

1 to 3 pounds of sodium hydrosulphite, 4 1 to 3 quarts of water solublevegetable oil, for example, sulphonated castor oil of 75 per cent.strength, and approximately 90 gallons of water.

In order to wet out the silk and neutralize any possible acidity of thesame before dyeing 1t, it may be passed a suificient number of timesthrough a cold alkaline bath, such as a bath containing water andcaustic soda 1n the proportions of about 90 gallons of 'water to 1 pintof 30 B. caustic soda soluion.

The dye bath is prepared by introducing all of the required amount ofcaustic soda and oil and two-thirds of the hydrosulphite and reducedcolor into the water in the jig, and the silk is passed through the bathone time. The remainder of the hydrosulphite and reduced color is thenadded and the silk is again passed through the bath while it is stillcold. With certain dyestufi's which do not have such a marked tendencyto become rapidly absorbed by the goods to be dyed, it is permissible tointroduce the whole amount of the dyestuif and the hydrosulphite intothe bath at the beginning of the dyeing operation, instead ofintroducing them in batches, as above mentioned. When found desirable,salts, such as Glaubers salt or sodium chloride, for example, may beadded to force the dyestufl" on to the silk.

After the silk has been given the cold bath treatment, the temperatureof the dye bath may then be raised to 110 F. with certain vat colorswhose characteristics adapt them to this treatment, while with others,the bath is kept cold all through the dyeing. The silk is 'passedthrough the bath a suflioient number of times to bring it to the desiredshade. Small amounts of reduced and dissolved color may be added to thedye bath for this purpose, if necessary. After the completion of thedyeing, the silk is passed severa1 times through cold water, using freshand then it is passed several water each time,

water bath that is overflowtimes through a necessary.

ing, with fresh .water being constantly introduced.

The silk is next acidified in a suitable acid bath, for example, a bathin which about one quart of 66 B. sulfuric acid is mixed with 90 gallonsof water. This acidification may be accomplished in the jig in which thedyeing took place, and the silk is passed through the bath the requisitenumber of times, say, twice, while it is cold. The silk is then washedWith water in the same manner as described above. In order to completethe oxidation of the dyestuff on the silk, it may be transferred to anoverhead reel bark of the ordinary type, which may have a capacity ofthree or four times that of the jig. An agent for promoting oxidation ofthe dyestuif is added. When soap, for example, is used for this purpose,the silk is soaped in the reel bark for about thirty minutes, using fromabout 6 to 12 pounds of soap, such as pure olive oil or Turkey red oilsoap containing approximately 25 per cent. ofwater, in about 17 5gallons of water, at a temperature of about 200 to 212 F. The silk isfinally washed thoroughly with water and in order to produce the properfeel or finish, it is acidulated. The acid bath may, for example,contain approximately 8 pounds of 28 per cent. acetic acid in 17 5gallons of cold water. If a volatile acid is used for this lastacidification, a subsequent wash with water is not absolutely However,if a non-volatile acid, such as sulfuric acid, is used, the subsequentwash is necessary.

In the accompanying drawings are shown illustrations of apparatus thatmay be utilized in carrying out the invention, in which Fig. 1 indicatesa side view of a jig; Fig. 2 is an end view of the same; Fig. 3 is aside view of an overhead reel bark and Fig. 4 is an end view of thesame. In the drawings, reference character 1 indicates the vat of a jigthat is provided with end rolls 2 and 3, and one or more idler rolls 4.The rolls 2 and 3 are mounted near the upper edge of the vat, and areprovided with convenient driving mechanism by which the same may bedriven at the proper speed, and can also be reversed so that the silk iswound upon one while it is unwound from the other one, and Vice versa,and at the same time it is passed beneath the idler roll 4 so as to beimmersed in the liquid in the va An important feature of this inventionhas been found to be that the rolls should be very accurately formed andmounted, so that as the silk is Wound upon the same, it will be freefrom wrinkles and will also be Wound up evenly. In order to do this, thejig is specially constructed to give perfect alignment of the rollers.In this way, the material is'permitted to roll up evenly after each dipin the dye bath, so that no edges are left unduly exposed to theoxidation of the air, thereby causing unevenness of color. It has alsobeen found important to provide each roll with a length of goods, suchas cotton, to which the ends of the silk are attached, with provisionfor the cotton to wrap around the silk roll when the end of the silk isreached. The Vat may be provided with an outlet 5 for emptyin the samewhen desired.

igs. 3 and 4 illustrate a convenient overhead reel bark in which thesoaping may take place, as above described. The soap and water areintroduced into the vat 6 and the silk is placed in the same andimmersed in the liquid. One end thereof is passed over the reel 7, whichis mounted above the surface of the liquid and is driven from anyconvenient source. The reel 7 is preferably covered with cloth-or othermaterial, to which the wet silk will adhere sufliciently to enable thesame to be drawn across and fall into the liquid on the other side ofthe reel. This operation may be reversed at pleasure, by reversing thedirection of travel of the reel and permitting the silk to pass over thesame in the other direction. During this soaping operation, the silk isexposed to the atmosphere and the oxidation of the dyest-ufi is causedto take place in such a manner that complete oxidation is obtaine c Ithas been found that substantially all of the vat dyes may be used inthis process such, for example, as anthra red RT Schultz No. 830,indanthrene blue GCD Schultz No. 842, and many others.

By dyeing silk piece goods, or piece goods containing silk inappreciable quantities, by the above process, we produce piece dyed silkgoods which have evenness of color and are fast to washing in soapywater, even at temperatures up to boiling or 212 F., and are fast toironing, perspiration, salt water, etc. It is also found that this dyedsilk does not bleed or give up color to soapy water at any temperatureup to the boiling point of the water. It is also unnecessary to use anymordant in connection with the dyeing operation.

We claim:

1. The process of dyeing silk goods in the piece, which comprisesreducing and dissolving a vat dye, introducing the same and solublevegetable oil, caustic soda, hydrosulphite and water into a vat andpassing the silk therethrough, washing the silk in water, acidfifyingthe same and oxidizing the dyestu 2. The process of dyeing silk goods inthe piece, which comprises reducing and dissolving a vat dye in alkalinewater containing a suitable reducing agent, introducing the same andsoluble vegetable oil, caustic soda, hydrosulphite and water into a vatand passing the silk therethrough, washing the silk in water, acidifyingthe same and oxidizing the dyestuif.

A and passing the silk 3. The process of dyeing silk piece, whichcomprises reducing and dissolving a vat dye in alkaline water containinga suitable reducing agent, introducing the same and soluble ble oil,caustic soda, hydrolnte and water into a vat and passing the goods inthe ing a suitable reducing agent, introducing in water, acidifying thesame, oxidizing the dyestufl and acidifying the silk.

6 The process of dyeing silk goods in the piece, which comprisesreducing and dissolving a vat dye in alkaline water containing asuitable reducing agent, introducing in water, acidifying the same,oxidizing the dyestufl" and acidifying the silk with an organic acid.

7. The process ofdyeing silk goods in the piece, which comprisesreducing and dissolving a vat dye in alkaline water containing asuitable reducing agent, introducing atmosphere substantially equallengths of time,-washing the'silkl in water, acidifying the same andoxidizing the dyestufl.

8. The process of dyeing silk goods in the piece, which comprisesreducing and dissolving a vat dye in alkaline water containing asuitable reducing agent, introducing the tion,

pounds of hydrosulphite and 90 gallons of water into a vat and passingthe silk therethrough, washing the silk in water,-

acidifying the same and oxidizing the dyestuff.

9.'The process of dyeing silk goods in the piece, which comprisesreducing and dissolving a vat d e in alkaline water containing asuitable re two-thirds ucing agent, introducing about of the same andabout 1 to 3 quarts of soluble vegetable oil, 1 to 4 quarts of causticsoda solution, 1 to 2 pounds of hydrosulphite and 90 gallons of waterinto a vat and passing the silk therethrough, adding the remainder ofthe dissolved color, Glaubers salt, and about one pound of hydrosulphiteto the bath, again passing the silk therethrough, wash acidifying thesame stuff.

LESLIE N. HOOD. WALTER M. SCOTT.

